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Full-Text Articles in Life Sciences

A Study Of Naturally Occurring Algicides Produced By Freshwater Algae, Denny O. Harris, Harry D. Caldwell Dec 1974

A Study Of Naturally Occurring Algicides Produced By Freshwater Algae, Denny O. Harris, Harry D. Caldwell

KWRRI Research Reports

The mode of action of the algicide produced by Pandorina morum was examined by exposing Volvox globator and isolates spinach chloroplasts to a partially purified algicide preparation. Oxygen evolution of Volvox, whole chloroplasts and broken chloroplasts (minus the Calvin cycle),was reduced indicating that the algicide inhibits the light reactions of photosynthesis. Oxygen evolution studies of other Volvocaceae confirmed the observation that Pandorina morum is not significantly influenced by its own inhibitor. Molecular weight approximation by gel filtration established that the inhibitor has a low molecular weight (probably below 100 mw). Field studies indicate that this algicide has tremendous potential as …


Feeding And Food Preferences By Three Sympatric Species Of Cyprinodontid Fishes, Lawrence J. Baer Jul 1974

Feeding And Food Preferences By Three Sympatric Species Of Cyprinodontid Fishes, Lawrence J. Baer

OES Theses and Dissertations

The feeding and food utilization by three sympatric species of cyprinodontid fishes was examined using a modified Ivlev Electivity Co-efficient. Results indicated that although Fundulus heteroalitus and Fundulus majalis are sympatric in the area examined,their usage of the available food source varied noticeably. The third investigated species, Cyprinodon variegatus, fed mainly upon a vegetal detritus food source varied by the consumption of invertebrate and vertebrate food items. Slight intra-specific variances of diet between crespuscular periods was also discussed.


Observations On The Distribution And Composition Of Zooplankton In Portions Of The Intracoastal Waterway, Virginia, O. Clair Hillard Jr. Apr 1974

Observations On The Distribution And Composition Of Zooplankton In Portions Of The Intracoastal Waterway, Virginia, O. Clair Hillard Jr.

Biological Sciences Theses & Dissertations

Five stations were established in the Southern Branch of the Elizabeth River, the Dismal Swamp Canal, the Albemarle and Chesapeake Canal and the North Landing River. Representative samples of zooplankton were taken from October 1971 to June 1972. A. total of 57 species were identified and discussions regarding seasonal distribution in relation to physical factors and circulation are presented.

The composition of the zooplankton was found to fluctuate greatly due to the variables characteristic of the study area. The combined effect of tidal flow with freshwater input in conjunction with drainage from the Great Dismal Swamp, results in isolated populations …


Lupin Agronomy: Time Of Planting, Seeding Rate And Variety In A Long Season Area., M. W. Perry Jan 1974

Lupin Agronomy: Time Of Planting, Seeding Rate And Variety In A Long Season Area., M. W. Perry

Experimental Summaries - Plant Research

To evaluate lupin varieties and agronomic practices in a long season district using a factorial experimental design. 74A16a Location - Warriup 57 km E. of .Albany. 74A16b Green Range, 70 km E. of Albany. Time of Planting (4) Seeding Rates (4) Varieties (4) Fertiliser.


Summary Of Experimental Work 1974, G Walton Jan 1974

Summary Of Experimental Work 1974, G Walton

Experimental Summaries - Plant Research

Lupinus albus cv WB2: Maximum yield response to 36 plants/m2 at Avondale (1973 and 1974) and Mt Barker Research Station in 1973 (achieved with 180 to 200 kg/ha seed rate), Maximum yield response to 48 plants/m2 at Chapman 1973 and 1974 and at Eradu 1974 (achieved with 220 tG 240 kg/ha). Very good yield results: Season - site Avondale 1973-3300, 1974-2250. kg/ha Chapman 1973-2800, 1974-2400. Mt Barker 1973-1900. 74A2 - Rates Of seeding for L, albus cv WB2. 74A21 - Rates of super on two lupin varieties. 74BR1 - Pasture regeneration after lupin survey. 74C4 - Rates of seeding L. …


Prostaglandins From Plexaura Homomalla: Ecology, Utilization And Conservation Of A Major Medical Marine Resource. A Symposium, Frederick M. Bayer, Alfred J. Weinheimer Jan 1974

Prostaglandins From Plexaura Homomalla: Ecology, Utilization And Conservation Of A Major Medical Marine Resource. A Symposium, Frederick M. Bayer, Alfred J. Weinheimer

Studies in Tropical Oceanography

No abstract provided.


Limnetic Zooplankton Dynamics In Beaver Reservoir Including An Inventory Of Copepod Species And An Evaluation Of Vertical Sampling Methods, Eugene H. Schmitz Jan 1974

Limnetic Zooplankton Dynamics In Beaver Reservoir Including An Inventory Of Copepod Species And An Evaluation Of Vertical Sampling Methods, Eugene H. Schmitz

Technical Reports

There can be little doubt that the development of primary food sources (i.e. plankton) is an important factor contributing to fish production. Applegate and Mullan (1968) report that an exceptional sport fish harvest is generally associated with the development of new reservoirs, although the precise reasons for such interrelations are not known. Kramer and Smith (1962) demonstrated the tendency of bass fingerlings to feed on Cladocera in proportion to the latter's abundance, and Hodson (1966) reported the same basic pattern for largemouth and spotted bass fingerlings in Beaver Reservoir. Applegate and Mullan (1969) analyzed the digestive tract contents of larval …


Effects Of Mosquito Control Chemicals On Aquatic Fauna, J. L. Lancaster Jr., M. V. Meisch Jan 1974

Effects Of Mosquito Control Chemicals On Aquatic Fauna, J. L. Lancaster Jr., M. V. Meisch

Technical Reports

No mosquito abatement districts have ever been organized in Arkansas. Mosquito control efforts have been largely adulticiding operations by either aerial application or ground thermal fogging machines. Practically no chemical applications have been directed at the larval stage in residual water in ditches and depressions from which adult populations arise. Some larviciding with ethyl parathion has been done in ricefields. Although the treatment is very effective in mosquito reduction, voluntary treatment has not been completely successful. Because relatively little insecticide has been used as a larvicide in Arkansas, it was possible to evaluate the effect of recommended larvicides on non-target …


Limnological, Ichthyological, And Parasitological Investigations On Arkansas Reservoris In Relation To Water Quality, John S. Carter, Carl E. Hoffman, Larry L. Olmsted, Raj V. Kilambi, Donald G. Cloutman, David A. Becker Jan 1974

Limnological, Ichthyological, And Parasitological Investigations On Arkansas Reservoris In Relation To Water Quality, John S. Carter, Carl E. Hoffman, Larry L. Olmsted, Raj V. Kilambi, Donald G. Cloutman, David A. Becker

Technical Reports

Lake Fort Smith, a 525 acre (212 ha) reservoir, was impounded in 1936 as a water supply for the city of Fort Smith. The reservoir is located on Clear Creek (Frog Bayou), a tributary of the Arkansas River, in the Boston Mountains 28 miles (45 km) northeast of the city of Fort Smith in Crawford County, Arkansas. A map and morphometric characteristics of Lake Fort Smith are given in Fig. 1 and Table I (Hoffman, 1951; Nelson, 1952). In 1956 Lake Shepherd Springs, a 750 acre (304 ha) impoundment, was created one mile upstream of Lake Fort Smith (Rorie, 1961). …


Summary Of 1974 Phosphorus And Sulphur Group, J W. Bowden, B. Scurr, R Lunt Jan 1974

Summary Of 1974 Phosphorus And Sulphur Group, J W. Bowden, B. Scurr, R Lunt

Experimental Summaries - Plant Research

Stocking x Super Rate - Merredin - 66M30. Twitcham - 62MB9. Kojonup - 68BR7. Maintenance P x S Trials - I. Residual Value - 66N07 and 66ME3. II. Wheatbelt Rate Trials - 67N011, 66LG1, 68LG1, 67NO5, 6NA3, 67GE2, 66M06 and 67M01. III. Wheatbelt Research Stations and Farmers- 65C5, 65A1, 65N5,69WH15 and 66N09. IV. Higher Rainfall Area Trials - 68B1, 68BU2, 68BR5,68AL3, 69E6, 69AL2 and 69AL3. Miscellaneous Trials - 74GE2, 74GE4, 74GE5,74JE3, 74LG4, 74M06, 74M07, 74TS3, 74NA3 74NA4, 74M07, 74TS4.


Pasture Deterioration - High Rainfall Areas, D J. Gillespie Jan 1974

Pasture Deterioration - High Rainfall Areas, D J. Gillespie

Experimental Summaries - Plant Research

a. Pasture deterioration - High rainfall areas - A farm at Karridale (near Augusta) exhibiting "classic" pasture deterioration symptoms was closely monitored throughout 1974. This farm has paddocks ranging from relatively newly sown pastures with a high clover percentage, few weeds and high dry matter production (resown 1973 and 1974), through to extremely poor pastures with as little as 3 % clover and a weed component of over 80% (resown 1970 and 1971)... b. Midland B competition studies (69Mt19) -This grazing trial was sown in 1969 to plots of pure Midland B, pure Woogenellup and to three mixtures of the …


Weed Trials 1974 Summary - Annual Ryegrass Control - Wild Oats - Cereal Tolerance To 2,4-D - Annual Ryegrass Toxicity, G. A. Pearce Jan 1974

Weed Trials 1974 Summary - Annual Ryegrass Control - Wild Oats - Cereal Tolerance To 2,4-D - Annual Ryegrass Toxicity, G. A. Pearce

Experimental Summaries - Plant Research

A herbicide trial and demonstration was commenced in 1973 and the treatment repeated in 1974. the objective was to control the annual ryegrass which was the dominant species and allow the scattered plants of sub clover to re-establish a clover dominant pasture. (See table) Despite the high reduction of seed stalks formed on some treatments in 1973 the ryegrass was only reduced by 50 per cent on the best treatment in 1974, The reduction in seed production in 1974 will no doubt further reduce the density of ryegrass in 1975 but eradication is unlikely. The value of burning in destroying …


Interim Summary 1974 Experiments, M L. Poole Jan 1974

Interim Summary 1974 Experiments, M L. Poole

Experimental Summaries - Plant Research

Data presented for: 74MT38 - Variety Trial - New rape and radish varieties 74MT27 - Rates of seed, time of planting on Crambe abyssinica 74GE'1 ·- Time of Seeding X Rate of Nitrogen on Sunflowers. Oilseed and Grain Legumes under Summer Irrigation. Sunflower Progress Report. Safflower Progress Report. Response of Oilseed Crops to Climate. Introduction - The results given in this report provide an interim record of 1974 experimental work with oilseed crops. An essential part of oilseed trial programme is an evaluation of the quantity and quality of oil produced by different species and varieties under a range of …


Summary Of Experimental Results - Wheat Protein Survey, R Weir Jan 1974

Summary Of Experimental Results - Wheat Protein Survey, R Weir

Experimental Summaries - Plant Research

Wheat protein survey Seeding rate x grain protein - 72NA33. Seeding rate x grain protein - 72M28. Temperature effects on flower set of lupin - 72GL4. Wheat protein survey - A survey of 130 farmers in 13 Shires of the high protein area around Merredin was undertaken in the few weeks prior to the 1972 harvest. Grain samples were forwarded by farmers after supplying site data including yield estimate. A soil sample was collected on which % soil N was determined. This information together with grain protein percentage was included in multiple regression, and stepwise regression analyses.


Long Term Rotation Trials - Annual Summary Of Results 1975, Ian Rowland Jan 1974

Long Term Rotation Trials - Annual Summary Of Results 1975, Ian Rowland

Experimental Summaries - Plant Research

Long term rotation trials: Results are the yield of grain harvested from crops grown after various lengths of pasture ley. W56H, 66M29, 67C13, 67N4, 68SG5,


Phytoplankton Distribution And Water Quality Indices For Lake Mead (Colorado River), Robert D. Staker, Robert W. Hoshaw, Lorne G. Everett Jan 1974

Phytoplankton Distribution And Water Quality Indices For Lake Mead (Colorado River), Robert D. Staker, Robert W. Hoshaw, Lorne G. Everett

Publications (WR)

Phytoplankton samples were collected in Lake Mend 6 times from September 1910 to June 1971 for 8 stations at depths of 0. 3, 5, 10, 20, and 30 m. These samples were processed through a Millipore filter apparatus and 79 planktonic algae were identified. Algal divisions represented were Bacillariophyta, 42 species; Chlorophyta, 18 ; Cyanophyta, 9; Chrysophyta, 3; Cryptophyta, 3; Pyrrophyta, 2; and Euglenophyta, 2. Blue-green algae were dominant in late summer and fall; green algae, diatoms, and, cryptomonads in winter; and green algae in spring. The early summer flora was best represented by the Chlorophyta, Cryptophyta, and Chrysophyta. Palmer's …


A Diurnal Zooplankton Migration Study In Lake Mead, Robert D. Staker Jan 1974

A Diurnal Zooplankton Migration Study In Lake Mead, Robert D. Staker

Publications (WR)

The diurnal vertical movement of zooplankton was first recorded in freshwater lakes by Weismann (1877) in Lake Constance (Bodensee), although Cuvier was credited with observing the migration of Daphniae in 1817 (Gushing, 1955). The migration is best observed in deep oligotrophic lakes and migrations of 50 m per day are described (Worthington, 1931). In addition, two species of chaetognaths are reported to migrate 400 m a day in marine waters off of Lisbon (Waterman and Berry, 1967) while Birge (1895) found little evidence of the phenomenon at all in Lake Mendota, Wisconsin.

Most zooplankton that migrate rise at night and …


Pasture Species Investigations - Wheat Belt (May, 1975), N. R. Mckeown Jan 1974

Pasture Species Investigations - Wheat Belt (May, 1975), N. R. Mckeown

Experimental Summaries - Plant Research

Results from trials comparing the growth and persistence of a number of annual pasture legumes are presented in this report. Rainfall conditions during the year are described briefly and a table of annual and growing season rainfall at relevant centres is appended. The experiments are grouped as follows according to average annual rainfall:- Zone A - Average annual rainfall > 400 mm Zone B - Average annual rainfall 345 - 400 mm Zone C - Average annual rainfall < 345 mm and then, further, on soil type. District Rainfall, 1974. 71LG16,, 72LG3, 74KA3, 70OTS2, 72TS5, 70NA3, 71TS22, 74NO3, 70ME4. The early break, with good rainfall continuing through most of the growing season, provided optimal conditions for most wheat belt trials. These conditions were in direct contrast to the dry years of the late 1960's and early 1970's. In 1974, legume growth on droughty deep sands should have been at its best. Serradella responded at Kukerin in direct relationship with earlier heavy dressings of potash. West of Three Springs, serradella and Tornafield medic stayed a little ahead of Harbinger medic and well ahead of Daliak sub. clover and rose clover. On deep sands at Marchagee and Arrino, subterranean clover was the only species worth considering. The failure of Eragrostis curvula to persist through the dry 1973-74 summer after good germination in late winter, indicates a need for more work on the establishment of this grass on deep sands. The low yields of dry matter at Tincurrin do not offer much incentive for such work, but Eragrostis, lupins and serradella probably give the best chance of pasturing the grossly infertile, erodable sands. Under favourable conditions, Geraldton sub. clover continued to show its versatility and aggressiveness. On an alkaline loamy sand at Lake King, waterlogged for periods during the winter, Dwalganup, Geraldton and Northam A produced more dry matter than a wide range of other pasture legumes. At Walgoolan, Geraldton maintained better than 503 content in mixtures with other sub. clover cultivars sown in 1970, while in a trial at Marchagee there was evidence of gradual, aggressive regeneration of Geraldton from a sparse pasture sown before the trial. Only two new legume species trials were planted in 1974, and these were not successful. Trial 74KA3, east of Katanning, demonstrated the need for timely planting. Had seed been available on time, the trial would have been planted before the onset of heavy rains and would have given better results. The failure of Tornafield and Harbinger on 74N03 should not weight the record unduly against these medics; :they have never excelled on clay loams, and they were sorely harassed by redlegged earthmite. The medics will not be replanted, but Northam A and Geraldton will be observed in 1975. :


Fallow Re-Assessment - Wheat Variety Investigations- Root Growth And Moisture Use, D Tennant Jan 1974

Fallow Re-Assessment - Wheat Variety Investigations- Root Growth And Moisture Use, D Tennant

Experimental Summaries - Plant Research

This report summarises progress and data available for the following investigations - Fallow Re-assessment - 72M29. Wheat Variety Investigations - Root Growth and Moisture Use. Location: Wongan Hills Research Station. Merredin Research Station.


Animal-Sediment Relations In A Tropical Lagoon: Discovery Bay, Jamaica, Robert C. Aller, Richard E. Dodge Jan 1974

Animal-Sediment Relations In A Tropical Lagoon: Discovery Bay, Jamaica, Robert C. Aller, Richard E. Dodge

Marine & Environmental Sciences Faculty Articles

The distribution of many macrobenthic species in the back-reef lagoon of Discovery Bay, Jamaica can be related to a gradient in bottom stability. This gradient is defined by increasing rates of biogenic reworking and sediment resuspension in the western part of the lagoon. Infaunal diversity and coral growth decrease in the western, unstable areas. The infauna of the carbonate sand consists mainly of deposit feeders. In the western lagoon, the feeding activities of this group result in high biogenic reworking rates (up to 6-7 cm/week) producing loose surface sediment easily resuspended by waves. A maximum, mean resuspension rate of 19 …


Lower York River Dissolved Oxygen Study, Robert A. Jordan Jan 1974

Lower York River Dissolved Oxygen Study, Robert A. Jordan

Reports

Past studies of the lowerr York River have shown that dissolved oxygen (D .O.) concentrations decline in the summer months, occasionally falling one mg/ 1 near the bottom in deep water (Brehmer,1970; Jordan,1973) . Due to this apparently natural phenomenon the Virginia water quality standards for D.O. in estuaries (4.0 mg/1 allowable minimum, 5 .0 mg/1 minimum daily average, U.S.. E.P.A,1971), are not met during this period . Therefore additional waste-water discharges into the lower York River will not initiate violation of the standards, but may exacerbate the existing situation by extending the area and the time period affected by …


Heavy Metal Concentrations In The Clam Rangia Cuneata From The Rappahannock And James Rivers, Robert Emile Croonenberghs Jan 1974

Heavy Metal Concentrations In The Clam Rangia Cuneata From The Rappahannock And James Rivers, Robert Emile Croonenberghs

Dissertations, Theses, and Masters Projects

This project investigated the feasibility of using the brackish water clam Rangia cuneata as a heavy metal pollution indicator, and further investigated the state of heavy metal pollution in the James River. Rangia cuneata were sampled in the fall of 1972 from the Rappahannock and James Rivers , and meats were analyzed by atomic absorption spectrophotometry for wet weight concentrations of copper, zinc, cadmium and lead. Levels of copper and zinc in Rangia cuneata were shown to be unaffected by clam size, spawning differences, salinity or distance upriver, and substrate grain size. Heavy metal concentrations in the oxidized channel sediments, …


Benthic Infaunal Community Formation In Dredged Areas In Hampton Roads, Virginia, Thomas Karl Duncan Jan 1974

Benthic Infaunal Community Formation In Dredged Areas In Hampton Roads, Virginia, Thomas Karl Duncan

Dissertations, Theses, and Masters Projects

The macrobenthic fauna in three dredged areas in Hampton Roads, Virginia was sampled for 14 months. Repopulation occurred very rapidly after the cessation of dredging, but the dominant species were generally not those previously recorded as mud-bottom dominants in the Hampton Roads area. The faunal changes through time somewhat agreed with those reported in classical successional sequences. This dissertation is from the Joint Program Degree from the College of William & Mary and University of Virginia and awarded by the University of Virginia.


1974 The Ecology And Control Of Doublegee (Emex Australis) And Emex Spinosa, D J. Gilbey Jan 1974

1974 The Ecology And Control Of Doublegee (Emex Australis) And Emex Spinosa, D J. Gilbey

Experimental Summaries - Plant Research

The objectives of the field experimental programme for 1974 were to - 1) Evaluate a technique to measure pasture loss as a result of doublegee infestation at Merredin, Wongan.Hills and Chapman. 2) Evaluate the effect of cultural and herbicide treatment combinations on the magnitude and distribution of viable doublegee seeds in the soil at Avondale, Merredin, Wongan Hills and Chapman. 3) Measure the magnitude and distribution of viable doublegee seeds in the soil from paddocks representing each year of a two crop, plus three year pastureley rotation at Avondale, Merredin, Wongan Hills and Chapman. 4) Screen herbicides for selective control …


The Response Of The Bivalve Mercenaria Mercenaria To Declining Oxygen Tensions, Dennis Walsh Jan 1974

The Response Of The Bivalve Mercenaria Mercenaria To Declining Oxygen Tensions, Dennis Walsh

Dissertations, Theses, and Masters Projects

No abstract provided.


Hydroids Of The Pelagic Sargassum Community Of The Gulf Stream And Sargasso Sea, David Holland Rackley Jan 1974

Hydroids Of The Pelagic Sargassum Community Of The Gulf Stream And Sargasso Sea, David Holland Rackley

Dissertations, Theses, and Masters Projects

No abstract provided.


The Effects Of Salinity Shocks And Low Oxygen Levels On Atpase Activity In Two Estuarine Bivalves, Marvin Ervis Hedgepeth Jan 1974

The Effects Of Salinity Shocks And Low Oxygen Levels On Atpase Activity In Two Estuarine Bivalves, Marvin Ervis Hedgepeth

Dissertations, Theses, and Masters Projects

No abstract provided.